Step 1

Preheat an oven to 180°C. Place the potatoes onto a baking tray and rub them in oil, salt and pepper. Bake them in the oven for 1 hour and 15 minutes, until the skins are crisp and dark and the insides are soft, dry and fluffy. Pour the milk into a medium saucepan and put it over a low heat. Add the butter and let it melt into the milk.

Step 2

When the potatoes are soft all the way through (you can test this with a small knife) cut them in half lengthwise and scoop the flesh into a mixing bowl, season and mash well (save the skins). Add the horseradish sauce and half of the milk and butter and stir just enough to combine.

Step 3

Grab a large coarse sieve and using a spatula or plastic paddle push the potato through into another saucepan, scraping the bottom regularly. Once all the potato is through put the pan over a low heat and add the remaining milk and butter to make a smooth, loose mix.

Step 4

Cover the purée with Cling Film and keep warm.

Step 5

Cut a thin slice of each lengthwise side of your large potatoes to get a flat 'steak' like potato about 2cm thick. Peel the skin off around the edges.

Step 6

Add the beef dripping to a large frying pan and put it over a high heat. Let the dripping melt then season the potato slices with plenty of salt and pepper and carefully place them into the pan. Turn the heat down to medium and leave them to fry for 5 minutes, until there is a deep golden brown crust. Turn and repeat on the other side then pour in 200ml of the beef stock so that it reaches halfway up the potato. Crush and peel the garlic cloves and add them to the pan with the thyme and rosemary.

Step 7

Put a lid on the pan and turn the heat down low. Simmer for 15 minutes, until the stock has almost evaporated and the potato is almost soft through - you can check this using a small knife. Remove the potatoes from the pan and pour in the remaining 300ml of beef stock. Skim any excess fat then leave it over a medium-high heat for 10-12 minutes, until it becomes a slightly sticky sauce. Strain and keep warm.

Step 8

Pour the 200ml of vegetable oil into a small saucepan and heat to 180°C. Carefully lower the fondant potatoes into the oil and fry for 2-3 minutes on each side, until they have a crisp crust again.

Step 9

Add the butter to another frying pan, add the crisp potatoes, then add the demi-glace and baste until glazed and sticky.

Step 10

Keep the oil at 180°C. Slice the leftover skins into thin matchsticks then lower into the preheated oil. Fry for a few minutes until golden brown and crisp then transfer onto a tray lined with kitchen towel. Season well with salt.

Step 11

Use a knife to separate the stalks and leaves of the chard. Put a large saucepan of water over a high heat and bring it to a boil. Season with salt and add the stalks. Boil for 10 minutes, then add the leaves and take it off the heat. After another minute drain the pan and squeeze the lemon juice over the chard. Toss it together and let it dry.

Step 12

Serve a scoop of purée per plate. Let it relax on the plate and top with a potato 'steak', followed by a handful of crisp skins. Place the chard next to the purée and serve. Serves 4